1. Field of the Invention
The present invention relates in general to microbend sensors, and in particular to a new and useful sensor which utilizes scintillating or fluorescing optical fibers as a source of light for such sensors.
2. Description of the Related Art
Optical fiber microbend sensors such as accelerometers, pressure transducers, displacement transducers and strain gages function by modulating the intensity of light in an optical fiber and relating the change in intensity to changes in the sensed parameter. Light from an LED, laser diode or other light source is provided to the sensor through an optical fiber. The light is modulated by the sensor and is returned to detecting optoelectronics. Various architectures have been devised to accomplish this supply of light to the sensor and return of the modulated signal, as shown in FIGS. 1 through 4. Commonly, the source and detection electronics and optics are incorporated in the same enclosure.
Sensors which operate in the "throughput" mode require two optical fibers (10, 12) between the optoelectronic (14) and the sensor (16) as shown in FIG. 1. Fiber (10) transmits the light from the source (14) to the sensor (16), and fiber (12) transmits the modulated light from the sensor (16) to detection means (26). This architecture provides for relatively low insertion loss and simplicity in the optoelectronics. "Single-ended" sensors as shown in FIG. 2, incorporate a retroreflector or mirror in the sensor (16) and require only a single fiber (11) between the optoelectronic (14) and the sensor, generally at the expense of higher insertion losses and increased complexity of the optoelectronics which now require a coupler (18). These two architectures are commonly known in the art and are the basis for virtually all intrinsic fiber optic sensors.
FIG. 3 shows a second example of the single ended sensor architecture and FIG. 4 shows a second example of the throughput version of conventional sensor architectures.